package org.bouncycastle.asn1.misc;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DEREncodable;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequence;

public class IDEACBCPar implements DEREncodable {
    ASN1OctetString iv;

    public static IDEACBCPar getInstance(Object o) {
        if (o instanceof IDEACBCPar) {
            return (IDEACBCPar) o;
        } else if (o instanceof ASN1Sequence) {
            return new IDEACBCPar((ASN1Sequence) o);
        }

        throw new IllegalArgumentException("unknown object in IDEACBCPar factory");
    }

    public IDEACBCPar(byte[] iv) {
        this.iv = new DEROctetString(iv);
    }

    public IDEACBCPar(ASN1Sequence seq) {
        if (seq.size() == 1) {
            iv = (ASN1OctetString) seq.getObjectAt(0);
        } else {
            iv = null;
        }
    }

    public byte[] getIV() {
        if (iv != null) {
            return iv.getOctets();
        } else {
            return null;
        }
    }

    /**
     * Produce an object suitable for an ASN1OutputStream.
     * 
     * <pre>
     * IDEA-CBCPar ::= SEQUENCE {
     *                      iv    OCTET STRING OPTIONAL -- exactly 8 octets
     *                  }
     * </pre>
     */
    public DERObject getDERObject() {
        ASN1EncodableVector v = new ASN1EncodableVector();

        if (iv != null) {
            v.add(iv);
        }

        return new DERSequence(v);
    }
}
